Surgical retractor systems and methods

ABSTRACT

Embodiments herein are generally directed to surgical retractor systems. In some embodiments, these retractor systems may be used in spinal fusion or other procedures that utilize a transforaminal approach.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. application Ser. No.14/630,684, filed Feb. 25, 2015, which is hereby incorporated byreference in its entirety for all purposes.

FIELD OF THE INVENTION

The present invention relates to systems for performing surgicalretraction and methods of use thereof.

BACKGROUND OF THE INVENTION

Many types of spinal irregularities can cause pain, limit range ofmotion, or injure the nervous system within the spinal column. Theseirregularities can result from, without limitation, trauma, tumor, discdegeneration, and disease. Often, these irregularities are treatedthrough a surgical procedure that may include, for example, immobilizinga portion of the spine. These treatments may involve, for example,replacing a damaged disc with an intervertebral implant and securing theadjacent vertebrae with a combination of screws and rods.

In order to perform these procedures, a surgical opening is created, anda device such as a retractor may be used to enlarge the opening andfacilitate access to the surgical site. The retractor may typicallyinclude one or more blades that can be adjusted to establish, provide,and/or maintain an appropriate opening that minimizes trauma tosurrounding tissue. There is a need for improved retractors whichprovide enhanced control of the retractor device.

SUMMARY OF THE INVENTION

To meet this and other needs, retractors, systems, and methods forperforming surgical retraction are provided. The retractors may allowfor dual and independent blade retraction, which can provide the surgeonwith additional control and an ability to limit the incision size. Theretraction may be controlled both medially and laterally, and each blademay be provided with an independent towing capability. In addition,blades may be provided with a universal mount or attachment allowingthem to be interchangeable with retractor systems and handheld retractordesigns. The blade designs may be selected, for example, based onpatient anatomy and surgeon preference.

Some embodiments herein are directed to a retractor system that caninclude a first arm comprising a towing assembly, the towing assemblycomprising an interface member coupled to a rotatable shaft, wherein theinterface member comprises a distal surface having a plurality ofprotrusions and receptacles; and a first blade comprising a through-holepassing from a first side surface to a second side surface andconfigured to reversibly receive the rotatable shaft therein, whereinthe first blade comprises a plurality of protrusions and receptaclesconfigured to intermesh with the plurality of protrusions andreceptacles of the distal surface of the first arm.

Other embodiments herein are directed to a retractor system that caninclude a first arm comprising a towing assembly, the towing assemblycomprising a rotatable shaft coupled to both a worm drive and aninterface member, the interface member comprising a star grind; a firstblade comprising a through-hole passing from a first side surface to asecond side surface and configured to reversibly receive the rotatableshaft therein, an interiorly-threaded passageway that intersects thethrough-hole, and a star grind on the first side surface configured tointerdigitate with the star grind of the first arm; and a retainingmember configured to reversibly engage the interiorly-threaded openingof the first blade and the rotatable shaft of the first arm.

Yet other embodiments herein are directed to a retractor system that caninclude a first arm comprising a towing assembly, the towing assemblycomprising a rotatable shaft coupled to both a worm drive and aninterface member, the interface member comprising a star grind; and afirst blade comprising a through-hole configured to reversibly receivethe rotatable shaft therein and a star grind configured to interdigitatewith the star grind of the first arm; wherein the first blade isconfigured to be pivotable relative to the first arm by an angle of atleast 180 degrees when the first blade is coupled to the first arm.

Some embodiments herein are directed to a method of operating aretractor system that can include providing a retractor system,comprising: a first arm comprising a towing assembly, the towingassembly comprising an interface member coupled to a rotatable shaft,wherein the interface member comprises a distal surface having aplurality of protrusions and receptacles; and a first blade comprising athrough-hole configured to receive the rotatable shaft therein and afirst side surface having a plurality of protrusions and receptacles,wherein the first side surface is configured to intermesh with thedistal surface of the first arm; reversibly coupling a first handle tothe first blade; reversibly coupling the first blade to the first arm,comprising: inserting the rotatable shaft of the first arm into thethrough-hole of the first blade; and threading a set screw through apassageway on the first blade; and actuating the towing assembly to towthe first blade relative to the first arm.

Other embodiments herein are directed to a method of operating aretractor system that can include providing a retractor system,comprising: a first arm comprising a towing assembly, the towingassembly comprising a rotatable shaft coupled to both a worm drive andan interface member having a star grind thereon; a first bladecomprising a through-hole configured to reversibly receive the rotatableshaft therein, an interiorly-threaded opening that intersects thethrough-hole, and a first side surface having a star grind configured tointerdigitate with the star grind of the first arm; and a retainingmember configured to reversibly engage the interiorly-threaded openingof the first blade and the rotatable shaft of the first arm; reversiblycoupling a first handle to the first blade; reversibly coupling thefirst blade to the first arm, comprising: inserting the rotatable shaftof the first arm into the through-hole of the first blade; threading theretaining member in the interiorly-threaded passageway and intoengagement with the rotatable shaft of the first arm; andinterdigitating the star grind of the first arm with the star grind ofthe first blade; and actuating the worm drive to tow the first bladerelative to the first arm.

Yet other embodiments herein are directed to a method of operating aretractor system that can include providing a retractor system,comprising: a first arm comprising a towing assembly, the towingassembly comprising a rotatable shaft coupled to both a worm drive andan interface member, the interface member comprising a star grind; and afirst blade comprising a through-hole configured to reversibly receivethe rotatable shaft therein and a first side surface having a star grindthereon, the star grind of the first surface configured to interdigitatewith the star grind of the first arm; reversibly coupling the firstblade to the first arm, comprising inserting the rotatable shaft of thefirst arm into the through-hole of the first blade and interdigitatingthe star grind of the first arm with the star grind of the first blade;and actuating the worm drive to pivot the first blade relative to thefirst arm by an angle in the range of from 1 degree to 360 degrees.

Some embodiments herein are directed to a retractor system comprising afirst arm comprising a towing assembly having an interface member, afirst blade member comprising a connector body and a blade extendingtherefrom, the connector body configured to engage the interface member,for example, with an interconnecting star grind, and a spring-loadedbutton mechanism configured to lock the first blade member to the firstarm at any desired position. The spring-loaded button mechanism mayinclude a button and a spring positioned within a cavity in the button.The button may include a first end configured to be depressed by a userand a second end which is received in the first blade member in a lockedposition and may extend outside the blade member in an unlockedposition. The button may define an opening extending therethrough whichis sized and configured to receive at least a portion of the rotatableshaft. The opening may be symmetrical or non-symmetrical in shape. Aportion of the opening may be defined by a curved surface configured toengage a groove in the rotatable shaft when in the locked position. Theinterface member of the towing assembly may also be spring-loaded byproviding a spring within a cavity in the towing assembly behind theinterface member. When the blade member is unlocked, the spring may beconfigured to cause the blade member to eject off the rotatable shaftand separate from the towing assembly.

Other embodiments herein are directed to radial and parallel handheldretractors. The handheld retractor may include first and second handles,first and second arms respectively associated with the first and secondhandles, and a pivotal connection between the first and second handlesand the first and second arms. In addition, first and second universalmounts may be respectively associated with the first and second arms.The first and second universal mounts each comprise an interface membercoupled to a rotatable shaft. The interface member comprises a distalsurface having a plurality of protrusions and receptacles, and the firstand second universal mounts may be configured to reversibly receivefirst and second blades, respectively. The first and second blademembers may each comprise a connector body and a blade extendingtherefrom. The connector body may have an internal cavity configured toreversibly receive the rotatable shaft therein. The first and secondblade members may each comprise a plurality of protrusions andreceptacles configured to intermesh with the plurality of protrusionsand receptacles of the respective interface members. In addition, anoptional pivot point may be located on each of the first and second armsthat allow the first and second handles to be angled relative to theblades, thereby conforming to a patient's anatomy. In one embodiment,the handheld retractor provides for radial movement of the blades. In analternative embodiment, the handheld retractor provides for parallelmovement of the blades.

The handheld retractor attachment interface and universal blades mayalso include any of the features described with respect to the midlineretractor system, including but not limited to, a spring-loaded buttonmechanism configured to lock the first and second blade members to thefirst and second universal mounts, respectively, at any desiredposition; the spring-loaded button mechanism includes a depressablebutton and a spring positioned within a cavity in the button; a springprovided within a cavity in the universal mount, such that when theblade member is unlocked, the spring is configured to cause the blademember to eject off the rotatable shaft and separate from the universalmount; the rotatable shaft comprising a circumferential groove on anexterior surface thereof, the groove configured to interface with thebutton in the blade member; and the like.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating certain embodiments of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present embodiments will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIGS. 1A-1B illustrate perspective views of a retractor assembly asdescribed herein;

FIG. 2A illustrates a cross-sectional view of a first arm as describedherein;

FIG. 2B illustrates a cross-sectional view of a towing assembly asdescribed herein;

FIG. 2C illustrates a perspective view of a first arm coupled to a rackas described herein;

FIG. 2D illustrates a perspective view of a first arm as describedherein;

FIG. 3A illustrates a cross-sectional view of a first arm coupled to afirst blade as described herein;

FIG. 4A illustrates a cross-sectional view of a first handle coupled toa first blade as described herein;

FIG. 4B illustrates a partial cross-sectional view of a first handlecoupled to a first blade as described herein;

FIGS. 4C-4D illustrate cross-sectional views of a first blade, firstarm, and first handle as described herein;

FIG. 5A illustrates a perspective view of a ratcheting assembly asdescribed herein;

FIGS. 5B-5F illustrate cross-sectional views of a ratcheting assembly asdescribed herein;

FIG. 6A shows a front view of a blade member as described herein;

FIGS. 6B and 6C show cross-sectional partial views of the blade membershown in FIG. 6A in locked and unlocked positions, respectively;

FIG. 6D is a close-up side view of the button as described herein;

FIGS. 6E and 6F show close-up side views of the blade member shown inFIG. 6A with the button in locked and unlocked positions, respectively;

FIG. 7A is a perspective view of one embodiment of a towing assembly asdescribed herein;

FIG. 7B is a side view of the towing assembly shown in FIG. 7A;

FIG. 7C is a perspective view of the rotatable shaft used in the towingassembly as described herein;

FIG. 7D is a cross-sectional view of the towing assembly shown in FIG.7A;

FIGS. 8A-8E depict various stages of connecting and disconnecting theblade member to the towing assembly of the retractor system as describedherein;

FIGS. 9A-9H depict various views of a radial handheld retractor withuniversal mounts for reversible attachment of the blades as describedherein;

FIGS. 10A-10C show various view of a parallel handheld retractor withuniversal mounts for reversible attachment of the blades as describedherein; and

FIGS. 11A-11E depict alternative views of a low-torque removable wingnutas described herein.

DETAILED DESCRIPTION

In a spinal fusion procedure, a damaged spinal disc may be removed andreplaced with an intervertebral implant (e.g., a cage, spacer, vertebralbody replacement, or other prosthetic). The adjacent vertebrae may bestabilized with a combination of screws and rods. As part of theprocedure, a retractor may be used to establish, enlarge, manipulate,and/or maintain a surgical opening, thereby facilitating the passage ofthe various implant devices and related tools. In some instances,different retractors may be used for different surgical approaches(e.g., anterior, posterior, transforaminal, lateral), due to the varyinganatomical features unique to each approach. For example, in a midlineincision transforaminal (e.g., TLIF) approach, the multifidis muscle mayneed to be separated from the spinous process and retracted outlaterally on both sides to the lamina. The retractor blades may thus beused to hold back soft tissue and muscle, and precise angling of theretractor's blades may depend at least in part on various factors,including the particular patient's anatomy and surgeon's preference.Accordingly, described herein are new and improved retractor systemsthat can enable retraction in a manual, handheld configuration as wellas in a mounted, linear configuration. Further described herein are newand improved retractor systems that include a blade that can be towed orpivoted by up to 360 degrees or more relative to an arm of the system.Overall, retractor systems disclosed herein may advantageously provideimproved blade manipulation, resulting in more precise tissueretraction. Although described herein with regards to midline TLIFprocedures, those skilled in the art may appreciate that the retractorsystems described herein may also be used in other surgical procedures.

Components of all of the devices disclosed herein can be made ofmaterials known to those skilled in the art, including metals (e.g.,titanium), metal alloys (e.g., stainless steel and cobalt-chromium),ceramics, polymers (e.g., poly ether ether ketone (PEEK), polyphenylenesulfone (PPSU), polysulfone (PSU), polycarbonate (PC), polyetherimide(PEI), polypropylene (PP), polyacetals, or mixtures or co-polymersthereof), allograft, and/or combinations thereof. In some embodiments,the devices may include radiolucent and/or radiopaque materials. Thecomponents can also be machined and/or manufactured using techniquesknown to those skilled in the art. For example, polymeric components maybe injection-molded or blow-molded.

As used herein the terms “proximal” and “distal” are utilized generallywith reference to a user (e.g., a surgeon) of the retractor assembliesdescribed herein. When used with reference to a rack, described furtherherein, the terms “lateral” and “medial” refer generally to the ends andthe middle of the rack, respectively. For example, a retractor armtraveling in a lateral direction may be traveling from a middle portionof the rack to an end portion of the rack, and a retractor arm travelingin a medial direction may be traveling from an end portion of the rackto a middle portion of the rack. These and other directional terms suchas “superior,” “inferior,” “top,” and “bottom,” and the like may be usedherein for descriptive purposes and do not limit the orientation(s) inwhich the devices may be used.

Some embodiments may include a two-bladed linear retractor with bothdual and independent blade retraction. The retraction may be controlledwith both a medial and lateral ratcheting mechanism. Each blade may alsohave an independent towing or pivoting capability. The linear retractormay feature a central table arm mount as well as pivoting arms to allowthe retractor to lie at approximately the patient's skin level.Different blade geometries may be used based on the patient anatomy andsurgeon preference. For example, the blades may be provided with aconvexity at the proximal end to cup under tissue and muscle to preventthe blades and retractor from floating upward.

Turning now to FIGS. 1A-5F, a retractor system 100 is illustrated inaccordance with embodiments described herein. As illustrated in FIGS.1A-B, the retractor system 100 can include a first arm 2 and a firstblade 4. In some embodiments, the retractor system 100 may also includea second arm 12 and a second blade 14. The retractor system 100 mayoptionally include one or more additional components, such as a firsthandle 6, a rack 8, and/or a second handle 16, as described herein. Theretractor system 100 may also include a table mount 10. In use, thefirst and second arms 2, 12 may be configured to translate at leastlaterally along the rack 8, and may thereby be configured to linearlyretract tissue and/or maintain or enlarge a surgical window. Thoseskilled in the art may appreciate that the second arm 12 and secondblade 14 may include some or all of the same features as the first arm 2and first blade 4, respectively. Thus, those skilled in the art mayappreciate that any description of the first arm 2 and first blade 4herein may also apply to the second arm 12 and second blade 14.

As illustrated in FIG. 2A, the first arm 2 can include a towing assembly18. In some embodiments, the first arm 2 may be jointed. In theseembodiments, the first arm 2 can also include a body 20, a base 22, anda connector 24 pivotably coupled therebetween. In some embodiments, thetowing assembly 18 can be at least partially located or housed withinthe body 20. In other embodiments, the towing assembly 18 may be atleast partially located or housed within another part of the first arm 2(e.g., the base 22 and/or the connector 24).

As illustrated in FIGS. 2A-B, the towing assembly 18 can include aninterface member 26 and a rotatable shaft 28. The rotatable shaft 28 canbe generally elongate and/or cylindrical, and can include a tapereddistal tip 34, as illustrated in FIG. 2B. The rotatable shaft 28 can beconfigured to rotate about a longitudinal axis. The rotatable shaft 28can also include a reduced-diameter section. For example, the rotatableshaft 28 can also include a circumferential channel or groove 36 on anexterior surface thereof. The groove 36 may extend partially or entirelyaround the circumference of the rotatable shaft 28.

The rotatable shaft 28 may be coupled to the interface member 26, forexample, by passing through an axial hole 30 of the interface member 26.The axial hole 30 may extend longitudinally along an entire length ofthe interface member 26. In some embodiments, the interface member 26may be configured to rotate with the rotatable shaft 28, but notrelative to (e.g., separately from) the rotatable shaft 28.

The interface member 26 can include an outer (e.g., distal and/orplanar) surface 32 that includes a plurality of protrusions (e.g.,bumps, peaks, teeth, and/or ridges) and/or receptacles (e.g., valleys,channels, depressions, and/or grooves) which may be interspersedtherebetween, as illustrated in FIG. 2C. In some embodiments, theprotrusions and receptacles may extend radially outward from the axialhole 30. As illustrated in FIG. 2C, the distal surface 32 can include aplurality of ridges and grooves extending radially around an opening ofthe axial hole 30. As described herein, the plurality of protrusions andreceptacles may be referred to as a star grind.

In alternative embodiments, an outer surface of the rotatable shaft 28,rather than the outer surface 32 of the interface member 26, may includea plurality of protrusions and/or receptacles. In these embodiments, therotatable shaft 28 may include an external spline (e.g., a plurality ofprotrusions and/or receptacles) extending longitudinally along anexternal surface thereof.

The towing assembly 18 can further include a gear assembly that includestwo or more gear members. The gear assembly can be configured to applytorque or a rotational force to the rotatable shaft 28. In someembodiments, the gear members may include parallel axes of rotation, andin other embodiments, the gear members may include perpendicular ororthogonal axes of rotation. As illustrated in FIG. 2B, the towingassembly 18 can include a worm drive, wherein the worm drive can includea worm 38 and a worm gear 40. As illustrated in FIG. 2D, the worm 38 mayinclude a plurality of threads configured to mesh with teeth of the wormgear 40. The worm gear 40 may be, for example, a spur gear or a helicalgear. In some embodiments, other types of gears and/or other geararrangements may be used.

The worm gear 40 may be coupled to the rotatable shaft 28. Asillustrated in FIGS. 2B and 2D, for example, the rotatable shaft 28 maybe configured to pass through an axial hole in the worm gear 40. In someembodiments, the worm gear 40 may be configured to rotate with therotatable shaft 28, but not relative to (e.g., separately from) therotatable shaft 28. As illustrated in FIG. 2D, the worm 38 may beconfigured to couple with or engage an actuator, such as a bolt, screw,pin, or hex head 42. In some embodiments, both the worm 38 and theactuator 42 may be coupled to a post 39, illustrated in FIGS. 2B and 2D.The hex head 42 may be configured to engage a driver such as ascrewdriver, wrench, Allen wrench, wingnut, or hex driver. The actuatormay include a socket configured to receive a portion of the drivertherein. For example, hex head 42 may include a hexagonal recess;however, those skilled in the art may appreciate that other actuatorshaving alternatively-shaped engagement recesses (e.g., square,triangular, pentagonal, heptagonal, and/or octagonal) may be used. Insome embodiments, the socket may have a width in the range of from about5 mm to about 10 mm. Those skilled in the art may appreciate that, inuse, a surgeon or other practitioner may use a driver to apply arotational force in a first direction to the worm 38, which may thencause the worm gear 40 and the rotatable shaft 28 to rotate in a firstdirection. Application of rotational force in a second, oppositedirection may also cause the rotatable shaft 28 to rotate in a seconddirection opposite the first.

In use, the worm gear 40 and the interface member 26 may be coupled tothe rotatable shaft 28 and subsequently placed into the body 20. In someembodiments, the body 20 may include a two-piece construction with topand bottom members secured by a plurality of set screws or pins 44, asillustrated in FIG. 2B. In other embodiments, the body 20 may include aone-piece construction (e.g., a unitary body). The body 20 may alsoinclude a cavity configured to receive at least a portion of the towingassembly 18 therein. The body 20 may be pivotably connected to theconnector 24. As illustrated in FIG. 2C, the body 20 can include aproximal projection 46. The proximal projection 46 can include a holepassing transversely therethrough. The transverse hole can be configuredto receive an elongate fastener such as pin 48 therein.

As illustrated in FIG. 2C, the connector 24 can include first and seconddistal prongs 50, 52 that are separated by a distal recess. Each of theprongs 50, 52 can include a hole passing transversely therethrough. Theholes may be coaxial. As illustrated in FIG. 2C, the holes may beconfigured to receive pin 48 or other fastener therein. In use, thoseskilled in the art may appreciate that the body 20 may be pivotablycoupled to the connector 24 by inserting the proximal projection 46 intothe distal recess between distal prongs 50, 52, and inserting pin 48into the resulting transverse passageway.

The connector 24 can also include first and second proximal prongs 54,56 that are separated by a proximal recess. Each of the prongs 54, 56can include a hole passing transversely therethrough. The holes may becoaxial and may be configured to receive a pin or other fastenertherein. The connector 24 may be pivotably coupled to the base 22 in amanner similar to that described with respect to the body 20. Forexample, the base 22 can include a distal projection 58. The distalprojection 58 can include a hole passing transversely therethrough andthat can be configured to receive a pin or other elongate fastenertherethrough. In use, the distal projection 58 of the base 22 can beinserted into the proximal recess of the connector 24, between proximalprongs 54, 56. A pin or other elongate fastener may then be insertedinto the resulting transverse passageway.

The arm 2 may be coupled to and/or may be configured to translatelinearly along a guide member, such as a rail, track, and/or rack 8, asillustrated in FIG. 2C. The arm 2 may be configured to translate in twodirections (e.g., medial and lateral) along the rack 8. The rack 8 maybe an elongate bar extending along a linear axis, and may include aplurality of teeth extending longitudinally thereon. The teeth may besymmetrical or asymmetrical (e.g., slanted). In some embodiments, thebase 22 may be configured to couple the first arm 2 to the rack 8. Forexample, the base 22 may include a channel or passageway 60 configuredto receive the rack 8 therein, as illustrated in FIGS. 2A and 2C. Thebase 22 can also include a translation member that can be configured totranslate the arm 2 along the rack 8. In some embodiments, thetranslation member can include a gear member, such as a pinion or othercircular gear, described further herein. The gear member can includegear teeth that mesh with the gear teeth on the rack 8. The gear teethmay be symmetrical or asymmetrical (e.g., slanted). The base 22 may alsoinclude an actuator 62, which may include a grip, handle, butterflyscrew, or knob, as illustrated in FIGS. 1B and 2C. The actuator 62 maybe configured to be coupled to the translation member. In use, rotationof the actuator 62 may cause the translation member to rotate. Therotational motion may be converted to linear motion as the translationmember translates along the rack 8. In some embodiments, the actuator 62may be tiltable or pivotable. This may reduce the profile of theactuator 62, which can be advantageous in environments where space maybe limited.

The base 22 can also include a locking member, such as a clamp. In someembodiments, the actuator 62 may be coupled to the locking member. Insome embodiments, the locking member may be configured to lock and/orsecure the first arm 2 at a particular lateral position along the rack 8and may prevent and/or inhibit further motion or translation relative tothe rack 8. In other embodiments, the locking member may prevent and/orinhibit motion or translation in a single direction along the rack 8(e.g., medially relative to the rack).

In some embodiments, the base 22 may include a lever, such as a pawl,that is configured to engage the teeth on the rack 8. The pawl may bespring-loaded and may allow motion of the arm 2 in a first directionalong the rack 8 while also preventing and/or inhibiting motion of thearm 2 in a second direction along the rack 8 (e.g., medially relative tothe rack 8). In these embodiments, the arm 2 may translate laterally toretract tissue, but may be prevented from returning towards its originalposition on the rack 8. In some embodiments, the pawl may be configuredto be disengageable so that the arm 2 may be allowed to translate in asecond direction. For example, the pawl may be disengaged from the rack8 and manually maintained in a disengaged position while simultaneouslytranslating the first arm 2 along the rack in the second direction. Inother embodiments, the pawl may include a blocking member that preventsthe pawl from re-engaging the rack 8.

An alternative embodiment of a base is illustrated in FIGS. 5A-F. Inthese embodiments, the base 22 can include a ratcheting assembly 160. Asillustrated in FIGS. 5A-B, the ratcheting assembly 160 can include apawl 162, a pinion 164, a blocking member 176, and an actuator 166(e.g., a release button or switch) coupled to the blocking member 176.As illustrated in FIG. 5B, the pawl 162 may include a tip 168 that maybe configured to engage the rack 8. Those skilled in the art mayappreciate that when the tip 168 is engaged with the rack 8, the firstarm 2 may not be able to translate along the rack 8. The pawl 162 mayalso include a handle 170. The pawl 162 may be configured to pivot abouta pin 174, illustrated in FIG. 5A. As illustrated in FIG. 5B, the pawl162 may be coupled to a torsion spring 172 that causes the tip 168 topivot towards the rack 8. As illustrated in FIG. 5C, the pawl 162 mayinclude a groove, channel, or cavity 180 therein. The cavity 180 mayhave an opening 182. The cavity 180 may be configured to receive atleast a portion of the blocking member 176 therein, for example, in aninterference fit. As illustrated in FIG. 5C, the actuator 166 and/or theblocking member 176 may be coupled to a compression spring 178. Theactuator 166 may be at least partially disposed, located, and/orpositioned within a depression 184 on the base 22.

The ratcheting assembly 160 may be advantageously configured to bedeactivateable, e.g., to transition reversibly between a neutral,deactivated configuration and an activated configuration. In theactivated configuration, the first arm 2 may be configured to travelfreely (e.g., without interference from and/or simultaneously depressingpawl 162) in one direction along the rack 8. To travel in the oppositedirection, the pawl 162 may need to be depressed to a partially-releasedposition, wherein the tip 168 disengages the rack 8, whilesimultaneously translating the first arm 2 in the opposite direction. Ifthe pawl 162 is not depressed to the partially-released position, and/orif it is released, the first arm 2 may be prevented from translating inthe opposite direction. In the neutral, deactivated configuration, thefirst arm 2 may be configured to travel freely (e.g., withoutinterference from and/or simultaneously depressing pawl 162) in bothdirections along the rack 8. In both configurations, the first arm 2 maytranslate by applying torque to the pinion 164, for example, through adriver, such as a screwdriver, wrench, or hex driver.

One example of a ratcheting assembly 160 in the activated configurationis illustrated in FIGS. 5A-C. As illustrated in FIG. 5C, when in theactivated configuration, at least a portion of the blocking member 176may be disposed and/or oriented within the cavity 180 of the pawl 162.When within the cavity 180, the blocking member 176 may not prevent thetip 168 of the pawl 162 from engaging the rack 8.

The ratcheting assembly 160 may be configured to transition from theactivated configuration to the neutral, deactivated configuration. Forexample, in use, a surgeon or other user may deactivate the ratchetingassembly 160 prior to coupling the first arm 2 to the first blade 4 asdescribed herein. Those skilled in the art may appreciate that if theratcheting assembly 160 were activated, the user might need to keep thepawl 162 in the partially-released position, possibly by hand, whilesimultaneously driving the actuator 166 and/or coupling the first arm 2and first blade 4. Advantageously, when in the deactivatedconfiguration, the process may be streamlined, as the user may not needto manually maintain the position of the pawl 162. By enabling the firstarm 2 to translate in a more simplified process, the deactivatedconfiguration may thereby promote, enable, and/or encourage easieralignment of the first arm 2 with the first blade 4.

To deactivate the ratcheting assembly 160, the pawl 162 may be depressedto a fully-released position, as illustrated in FIG. 5D-E. Asillustrated in FIG. 5E, when the pawl 162 is depressed (e.g., squeezedand/or pressed) to a fully-released position, the blocking member 176may be released from the cavity 180. Furthermore, the compression spring178 may be released, which may pull the blocking member 176 away (e.g.,out of alignment) from the opening 182 of the cavity 180, and which mayalso pull the actuator 166 out of the depression 184. As illustrated inFIGS. 5E-F, when in the deactivated configuration, the blocking member176 may block, inhibit, and/or prevent the pawl 162 from engaging therack 8.

The ratcheting assembly 160 may also be configured to transition fromthe deactivated configuration to the activated configuration. Forexample, in use, a surgeon or other user may activate the ratchetingassembly 160 after coupling the first arm 2 to the first blade 4 asdescribed herein, and/or prior to performing a surgical retractionprocedure. Advantageously, activation of the ratcheting assembly 160 mayprevent and/or inhibit the first arm 2 from inadvertently translating ina return direction and/or shrinking the retraction window.

To activate (or reactivate) the ratcheting assembly 160, the actuatormay be depressed (e.g., pressed and/or pushed) at least partially intothe depression 184. The compression spring 178 may be compressed, andthe blocking member 176 may be positioned (e.g., pushed) into alignmentwith the opening 182 of the cavity 180, as illustrated in FIG. 5C.

The rack 8 may be configured to be coupled to a table, cart, tray,and/or other support structure, which can optionally provide increasedstability. In these embodiments, table mount 10, as illustrated in FIGS.1A-B, may be used to couple the rack 8 to the table. In someembodiments, the table mount 10 may include a first engagement member,such as a receptacle, configured to engage or receive the rack 8therethrough, a second engagement member, such as a receptacleconfigured to engage or receive a portion of the table therein, and aclamping member configured to couple (e.g., clamp and/or secure) therack 8 to the table.

In other embodiments, the system 100 may be configured to be handheld.In some embodiments, the first and second arms may be coupled togetherat a pivot point and/or may be configured to pivot relative to eachother. The handheld system may also be self-retaining, e.g., may includea ratchet assembly configured to maintain an angle or relativeorientation of the first and second arms. By way of example, thehandheld system may include a weitlaner-type device that provides forlinear retraction through the use of a free pivoting arm and independenttowing capabilities. Once the midline incision has been made and themuscle released from the spinous process, a dilator or speculum may beutilized to measure the required blade length. Blade handles may beattached to the necessary blade lengths, which can be used to manuallyretract the tissue and muscle out laterally to both sides of the spinousprocess. The linear retractors can be inserted into the blades from aside approach and secured. The blade handles may then be removed. Theretractor can then be retracted and towed to provide access to thesurgical area.

The first blade 4 may be configured to be reversibly coupled with thefirst arm 2, as illustrated in FIGS. 1A-B. The retractor system 100 mayalso include second blade 14, which may be configured to be reversiblycoupled with the second arm 12. The first and/or second blades 4, 14 maybe generally elongate with a first (e.g., proximal or top) endconfigured to couple with the first and second arms 2, 12 and a second(e.g., distal or bottom) end configured to engage or contact tissue. Asdescribed herein, the first and/or second blades 4, 14 mayadvantageously be configured to be pivotable relative to the firstand/or second arms 2, 12. In some embodiments, the first and/or secondblades 4, 14, when coupled to the first and/or second arms 2, 12, may beconfigured to pivot at an angle in the range of from 1 degree to 360degrees relative to the first and/or second arms 2, 12. For example, inone embodiment, the first and/or second blades 4, 14, when coupled tothe first and/or second arms 2, 12, may be configured to pivot at anangle in the range of from 1 degree to 180 degrees relative to the firstand/or second arms 2, 12. In other embodiments, the first and/or secondblades 4, 14, when coupled to the first and/or second arms 2, 12, may beconfigured to pivot at an angle of at least 10, 20, 30, 40, 50, 60, 70,80, 90, 180 degrees, or more, relative to the first and/or second arms2, 12.

Those skilled in the art may appreciate that the second blade 14 mayhave some or all of the same features as the first blade 4, describedherein. As illustrated in FIG. 3A, the first blade 4 can include athrough-hole 64 that may be configured to reversibly receive at least aportion of the rotatable shaft 28 therein. The through-hole 64 may belocated at the first (e.g., proximal or top) end of the first blade 4.The through-hole 64 can pass transversely across (e.g., parallel to ashort axis of) the first blade 4 from a first side surface 66 to asecond side surface 68. In some embodiments, the through-hole 64 caninclude a constant diameter. In other embodiments, it may have avariable diameter. For example, the through-hole 64 can include enlargedfirst and second openings 74, 76, as illustrated in FIG. 4C.

In some embodiments, the first blade 2 may include a multi-piececonstruction. For example, the first blade may include a first interfacemember 70 and a second interface member 72, as illustrated in FIGS. 3Aand 4C. The first and second interface members 70, 72 may include atleast some of the features of the interface member 26 of the towingassembly 18. For example, the first and second interface members 70, 72may each include an axial hole. The first and second interface members70, 72 may be inserted into the first and second openings 74, 76 and theaxial holes thereof may at least partially define the through-hole 64.In some embodiments, when in an assembled configuration, the first andsecond interface members 70, 72 may not be pivotable and/or rotatablerelative to the first blade 4.

The first interface member 70 and the second interface member 72 mayeach have a first side surface 66 and a second side surface 68,respectively, as illustrated in FIGS. 3A and 4C. The first and/or secondside surfaces 66, 68 may include a plurality of protrusions, e.g.,bumps, peaks, teeth, and/or ridges, and receptacles, e.g., valleys,channels, depressions, and/or grooves, which may be interspersedtherebetween, as illustrated with respect to the second side surface 68in FIG. 3A. In some embodiments, the protrusions and receptacles mayextend radially outward from the through-hole 64. As illustrated in FIG.3A, the second side surface 68 can include a plurality of ridges andgrooves extending radially around an opening of the through-hole 64. Asdescribed herein, the plurality of protrusions and receptacles may bereferred to as a star grind. The plurality of protrusions andreceptacles may advantageously be configured to intermesh and/orinterdigitate with the protrusions and receptacles on the distal surface32 of the first arm 2.

In other embodiments, the first blade 4 may be a unitary body, e.g., theprotrusions and receptacles may be machined thereon. Those skilled inthe art may appreciate that in these embodiments, the first and secondside surfaces 66, 68 may refer to side surfaces of the first blade 4.

In alternative embodiments, the through-hole 64, rather than the firstand/or second side surfaces 66, 68, may include a plurality ofprotrusions and/or receptacles. In these embodiments, the through-hole64 may include an internal spline (e.g., a plurality of protrusionsand/or receptacles) extending longitudinally along an internal surfacethereof. Those skilled in the art may appreciate that the internalspline of the through-hole 64 may be configured to mesh and/orinterdigitate with the external spline of the rotatable shaft 28, suchthat rotation of the rotatable shaft 28 may cause rotation of the firstblade 4.

As illustrated in FIG. 4C, described further herein, the first blade 4may include an opening, e.g., passageway 78. Accordingly, in someembodiments, the passageway 78 may be interiorly-threaded. Thepassageway 78 may have a first opening 80 on a proximal (e.g., top)surface of the blade 4. The passageway 78 may intersect, beperpendicular to, and/or may be in fluid communication with thethrough-hole 64. The passageway 78 may be configured to receive and/orcouple with a retaining member or fastener, such as a set screw 82. Asillustrated in FIG. 4C, the set screw 82 may include a stem having alength that is greater than a length of the passageway 78. Accordingly,the stem of the set screw 82 may be configured to enter the through-hole64. The set screw 82 may be configured to reversibly engage (e.g.,couple, mate, and/or contact) the first blade 4 and the rotatable shaft28 of the first arm 2, for example, by threading into and/or out of thethrough-hole 64.

In some embodiments, the first blade 4 may include a curved body betweenthe first and second ends that is curved about a longitudinal axis. Inother embodiments, the first blade 4 may include a planar body. Thesecond end can include one or more features configured to engage theretracted tissue. In some embodiments, the second end can curve or bendat least partially (e.g., approximately 90 degrees) towards the firstend to define a tip that may be configured to cup under or penetratebelow the retracted tissue, thereby anchoring or securing the blade andreducing unintentional movement of the system. In some embodiments, thetip may include prongs or teeth. In other embodiments, the tip may beblunt. The tip may be concave, convex, or planar. In some embodiments,the body portion of the first blade 4 may be solid; in otherembodiments, it may be fenestrated. The first blade 4 can includerounded, dull, and/or blunt edges that may advantageously minimizeand/or reduce trauma to retracted tissue. In some embodiments, the firstblade 4 can include at least one longitudinally-extending holeconfigured to receive one or more instruments such as a Kirschner wire,aspirator, and/or fiber optic light source.

As illustrated in FIG. 1A, in some embodiments the retractor system 100can include first handle 6. The first handle 6 can be configured toreversibly (e.g., releasably) couple with the first blade 4. Turning toFIGS. 4A-B, the first handle 6 can include a clamping member 84, arotatable driver 86, an actuator 88, and/or an external sleeve 90.

As illustrated in FIG. 4A, the clamping member 84 can be configured toengage the first blade 4. The clamping member 84 can include a cannula92 extending axially (e.g., longitudinally) therethrough. The clampingmember 84 can include a distal section 110, a proximal section 114, anda middle section 112 therebetween. The middle section 112 can include atapered section 116 having a tapered outer diameter and/or a cylindricalsection 118 having a constant outer diameter. As illustrated in FIG. 4A,the tapered section 116 may be distal to the cylindrical section 118. Inthese embodiments, the tapered section 116 may be located between thecylindrical section 118 and the distal section 110. The proximal section114 and/or the distal section 110 may include a constant outer diameter(e.g., may be cylindrical). The distal section 110 may have an outerdiameter that is greater than that of the cylindrical section 118. Theproximal section 114 may have an outer diameter that is less than thatof the cylindrical section 118. Furthermore, the proximal section 114may be directly adjacent to (e.g., connected to) the cylindrical section118. In these embodiments, the clamping member 84 may include anexterior shoulder or ledge (e.g., on an outer surface) at the transitionpoint between the proximal section 114 and the cylindrical section 118.As illustrated in FIG. 4A, the proximal section 114 may also include anengagement feature, such as external threading.

The distal section 110 can be split into first and second jaws 94, 96.In embodiments where the distal section 110 has an outer diameter thatis greater than that of the cylindrical section 118, the first andsecond jaws 94, 96 may splay outwards (e.g., away from a longitudinalaxis thereof). The first and second jaws 94, 96 may be separated by alongitudinal channel or gap. The first and second jaws 94, 96 and/or thelongitudinal channel may be symmetrical. The longitudinal channel mayhave a width that is variable in some embodiments, and constant in otherembodiments. For example, in some embodiments, the longitudinal channelmay include an enlarged proximal end, e.g., a proximal section having awidth that is greater than that of a distal section thereof. Inembodiments where the longitudinal channel includes a constant width, itmay also have a rectangular longitudinal cross-section. In someembodiments, the longitudinal channel or gap may be compressible,contractable, and/or constrictable, and may thereby be configured tobring the first and second jaws 94, 96 closer together.

At least one of the first and second jaws 94, 96 can include aninwardly-extending (e.g., radially-extending) projection or protrusion98, 102 along an inner surface thereof. In some embodiments, theprotrusion 98, 102 can define a transverse ledge or shelf along theinner surface of the first and second jaws 94, 96. In some embodiments,the protrusion 98, 102 may be configured to mate with (e.g., be receivedwithin) a groove or slot on an outer surface of the first blade 4.

The cannula 92 of the clamping member 84 can include a distal section104, a proximal section 106, and a tapered section 108 therebetween. Insome embodiments, the distal section 104 may have a diameter that isgreater than a diameter of the proximal section 106. In otherembodiments, the distal section 104 may have a diameter that is lessthan a diameter of the proximal section 106. The tapered section 108 maybe linearly tapered or ramped (e.g., frustoconical). In otherembodiments, the tapered section 108 may include a curved taperedsurface. The tapered section 108 may be generally overlapping with thetapered section 116 of the clamping member 84.

The rotatable driver 86 can include a knob 122 and a shaft 124 extendingtherefrom. In some embodiments, the knob 122 may be located at aproximal end and the shaft 124 may extend distally therefrom. The shaft124 can include a body portion 130 and a distal end 126. The bodyportion 130 may be an elongate, solid, and/or cylindrical rod. Asillustrated in FIG. 4A, at least a portion of the shaft 124 may beconfigured to extend at least partially through the cannula 92 of theclamping member 84. In some embodiments, the distal end 126 may beenlarged (e.g., may have an outer diameter greater than that of the bodyportion 130). In these embodiments, the shaft 124 may also include atapered portion 132 located and configured to transition between thebody portion 130 and the distal end 126. The distal end 126 may alsoinclude a socket 128. The socket 128 may be configured to receive and/orengage a fastener (e.g., set screw 82) therein. In some embodiments, thesocket 128 may include a hexagonal transverse internal cross-section. Inuse, the rotatable driver 86 may be configured to drive a fastener,e.g., that is disposed within the socket 128. Those skilled in the artmay appreciate that the rotatable drive 86 may be configured to rotateand/or spin (e.g., along a longitudinal axis) relative to the clampingmember 84.

As illustrated in FIG. 4A, the actuator 88 can include a cannula 134extending longitudinally (e.g., along a longitudinal axis) therethrough.The cannula 134 can be configured to receive at least a portion of theclamping member 84 and/or rotatable driver 86 therein. The cannula 134can define an inner surface of the actuator 88. In some embodiments, theinterior surface can be configured to engage and/or mate with theclamping member 84. For example, in some embodiments, at least a portionof the interior surface can include threading (e.g., interiorly-threadedportion 136). In these embodiments, the interiorly-threaded portion 136of the actuator 88 can be configured to engage and/or mate with thethreaded proximal section 114 of the clamping member 84.

The actuator 88 can include a proximal section 138, a distal section140, and a middle section 142 therebetween. In some embodiments, atleast one of these sections may include a constant (e.g., cylindrical)outer diameter. In other embodiments, at least one of these sections mayinclude a variable (e.g., tapered) outer diameter. In yet otherembodiments, all of these sections may include a constant outerdiameter. In these embodiments, the outer diameters of each section maybe the same or different (e.g., one or more sections may be larger thanothers). For example, as illustrated in FIG. 4A, the middle section 142can have an outer diameter that is less than both an outer diameter ofthe proximal section 138 and an outer diameter of the distal section140. The distal section 140 can also have an outer diameter that is lessthan that of the proximal section 138. In use, the actuator 88 may beconfigured to rotate relative to the clamping member 84 and/or theexternal sleeve 90.

The external sleeve 90 may include a cannula 144 extendinglongitudinally (e.g., along a longitudinal axis) therethrough. Thecannula 144 may be configured to receive at least a portion of theclamping member 84 therein. The cannula 144 can define an inner surfaceof the external sleeve 90. The cannula 144 may have a constant orvariable diameter. In some embodiments, the cannula 144 may include twoor more sections, each having a different, constant diameter. Forexample, the cannula 144 may include a plurality of cylindricalsections, each having a different diameter. As illustrated in FIG. 4A,the cannula 144 can include a proximal section 146 and a distal section148. The proximal and distal sections 146, 148 may each include aconstant diameter. Additionally, the diameter of the proximal section146 of the cannula 144 may be less than that of the distal section 148.Accordingly, the external sleeve 90 may include an internal shoulder orledge 150 at a transition point between the proximal and distal sections146, 148.

The external sleeve 90 may also include a proximal extension member 152,as illustrated in FIG. 4A. The proximal extension member 152 may extendfrom at least a portion of a proximal end thereof. In some embodiments,the proximal extension member 152 may take the shape of a longitudinalsection of a hollow cylinder, hose, or pipe. The proximal extensionmember 152 may have a curved inner surface that curves along alongitudinal axis thereof. The curved inner surface may have a radius ofcurvature that is equal to or slightly larger than a radius of curvatureof the middle section 142 of the actuator 88. The proximal extensionmember 152 may further include a partially-circumferential (e.g.,C-shaped) inner groove 154. In some embodiments, at least a portion ofthe actuator 88 may be configured to engage with, interlock with, and/ornest in at least a portion of the proximal extension member 152. Forexample, the distal section 140 of the actuator 88 may be configured tobe received within the inner groove 154 of the external sleeve 90. As aresult, the actuator 88 and the external sleeve 90 may be configured totranslate (e.g., slide) together longitudinally. Additionally, theactuator 88 and/or external sleeve 90 may be configured to rotate orspin relative to each other, wherein the distal section 140 of theactuator 88 may rotate or spin within the inner groove 154 of theexternal sleeve 90.

Embodiments herein are also directed to methods of installing and/orusing the retractor system 100. The retractor systems described hereinmay be used in a wide variety of surgical procedures to retract tissueand/or maintain or enlarge a surgical window. In some embodiments, theretractor systems may be used in a spinal surgery, such as a fusion ordisc replacement procedure. The retractor systems may be used in fusionprocedures that approach a patient's spine from a variety of differentangles (e.g., anterior, posterior, lateral, and/or transforaminal). Insome embodiments, the retractor systems may be used or installed as partof a midline-incision transforaminal (e.g., TLIF) approach. In theseembodiments, a user may make a midline incision along a spinous process.Using a cannula or muscle dissector, the user may release the multifidismuscle from the spinous process and measure for the appropriate bladelength before installing and/or using the retractor system 100 (e.g.,before reversibly coupling the first blade 4 to the first handle 6and/or first arm 2).

Embodiments directed to methods of installing and/or using the retractorsystem 100 may include the step of providing a retractor system asdescribed herein that includes first arm 2, first blade 4, and/or firsthandle 6. These embodiments can also include reversibly coupling thefirst blade 4 with the first handle 6. This step can include insertingat least a portion of the first blade 4 between the first and secondjaws 94, 96 of the clamping member of the first handle 6, asillustrated, for example, in FIGS. 4A-B. In some embodiments, the firstand second jaws 94, 96 may include an internal protrusion 98, 102, asdescribed herein. In these embodiments, this step can also includeinserting or mating the protrusion 98, 102 with a corresponding grooveor channel on the first blade 4. In some embodiments, the first blade 4may also include a set screw 82 that is at least partially threaded intopassageway 78, as illustrated in FIGS. 4C-D, described further herein.In these embodiments, the step of reversibly coupling the first handle 6to the first blade 4 may include coupling the set screw 82 with therotatable driver 86, for example, by inserting a head of the set screw82 at least partially into socket 128 on the distal end 126 of the shaft124 of the rotatable driver 86, as illustrated in FIG. 4A. Those skilledin the art may appreciate that in this configuration, rotation of therotatable driver 86 may result in rotation of the set screw 82, therebycausing the set screw 82 to travel through the passageway 78.Alternatively, the quick connection blade attachment concept describedelsewhere herein may be used.

Once the first blade 4 is positioned between the first and second jaws94, 96, the first and second jaws 94, 96 may be tightened, secured,and/or engaged around the portion of the first blade 4 that is disposedtherebetween. This step may include rotating the actuator 88 of thefirst handle 6 in a first direction. As illustrated in FIG. 4A, as theactuator 88 is threaded along the clamping member 84 in a firstdirection (e.g., downwards and/or distally), the actuator 88 may pushthe external sleeve 90 in the same direction. The external sleeve 90 maytranslate and/or slide over the clamping member 84. As described herein,in some embodiments, the clamping member 84 may include a cylindricalsection 118, a distal section 110, and a tapered section 116therebetween. The distal section 110 can have a larger outer diameterthan the cylindrical section 118. Tapered section 116 can have avariable outer diameter that is equal to that of the cylindrical section118 at a proximal end and equal to that of the distal section 110 at adistal end (e.g., the tapered section 116 may have an outer diameterthat increases in a distal direction). As the external sleeve 90 passesover the tapered section 116, it may compress the longitudinal channelseparating the first and second jaws 94, 96, thereby squeezing and/orclamping the first and second jaws 94, 96 together around the firstblade 4. The external sleeve 90 may continue to travel distally untilthe inner ledge 150 of the external sleeve 90 contacts the outer ledge120 of the clamping member 84.

Advantageously, the coupled first handle 6 and first blade 4 may be usedas an independent device for handheld retraction, and may be referred toherein as a handheld retractor assembly. Thus, in some embodiments, themethod of installing and/or using the retractor system 100 may includemanually positioning the reversibly-coupled first handle 6 and firstblade 4, which may include manually retracting tissue, prior toreversibly coupling the first blade 4 to the first arm 2. In someembodiments, the second handle 16 and second blade 14 may also bereversibly coupled and manually positioned along with the coupled firsthandle 6 and first blade 4. In some embodiments, the handheld retractorassembly may advantageously provide a user or operator with increasedfreedom and/or improved blade manipulation, as compared to, for example,a retractor system that is solely configured for linear retraction viamounting to an arm, frame, or other scaffolding. Simpler handheldretractors may allow for easier retraction or may provide an alternativefor longer constructs, for example.

The first blade 4 may be reversibly coupled to the first arm 2. When thefirst blade 4 is coupled to the first arm 2, the first blade 4 may beconfigured to rotate with the rotating shaft 28 and/or interface member26. Additionally, the first blade 4 may not be able to rotateindependently from the rotatable shaft 28 and/or the interface member26. This step may include inserting the rotatable shaft 28 of the firstarm 2 into the through-hole 64 of the first blade 4, as illustrated inFIGS. 4C-D. The retaining member (e.g., set screw 82) may then bethreaded at least partially through the passageway 78 on the first blade4. Any suitable driver may be used to thread the set screw 82 throughthe passageway 78 of the first blade 4. In some embodiments, this stepmay be accomplished at least in part by rotating the rotatable driver86, which may apply torque to the set screw 82.

The step of threading the set screw 82 at least partially through thepassageway 78 may include threading the set screw 82 to a first positionwherein the first blade 4 is fastened to the first arm 2, as illustratedin FIG. 4C. In this position, the first blade 4 and the first arm 2 maybe connected, but the first side surface 66 of the first blade 4 may bespaced apart from the outer surface 32 of the interface member 26 of thefirst arm by a gap 156. This position may advantageously enable asurgeon or other user to make additional manipulations and/oradjustments to the orientation and/or location of the first blade 4prior to coupling it to the first arm 2. As the set screw 82 continuesto be threaded through the passageway 78, a tip 158 of the set screw 82may engage the rotatable shaft 28 and pull the rotatable shaft 28towards the first blade 4. The set screw 82 may continue to be threadedthrough the passageway 78 until it achieves a second position,illustrated in FIG. 4D, wherein the tip 158 of the set screw 82 isnested within the circumferential groove 36 of the rotatable shaft 28.As the rotatable shaft 28 is pulled toward the first blade 4, theinterface member 26 may also be pulled towards the first blade 4. Thus,at this position, the protrusions and receptacles (e.g., star grind) ofthe first side surface 66 of the first blade 4 may intermesh and/orinterdigitate with the protrusions and receptacles (e.g., star grind) ofthe distal surface 32 of the first arm 2. Those skilled in the art mayappreciate that the star grinds may advantageously self-align, e.g.,they can intermesh in the absence of pre-alignment by a surgeon or otheruser.

As described herein, the first blade 4 and the first handle 6 may bereversibly coupled. After the first blade 4 is reversibly coupled to thefirst arm 2, the first handle 6 may be uncoupled (e.g., disengaged) fromthe first blade 4. To uncouple the first blade 4 and the first handle 6,the actuator 88 of the first handle 6 may be rotated in a seconddirection, which may cause the actuator 88 to be threaded along theclamping member 84 in a second direction opposite the first (e.g.,upwards and/or proximally). The actuator 88 may pull the external sleeve90 in the same direction, thereby releasing the external sleeve 90 fromthe tapered section 116 of the clamping member 84. Additionally, as theactuator 88 continues to travel in an upwards and/or proximal direction,it may exert an upwards and/or proximally-directed force on the knob 122of the rotatable driver 86. The rotatable driver 86 may then be pulledproximally. The tapered section 132 of the rotatable driver 86 may thencontact and/or exert force on an inner surface of the external sleeve 90at the tapered section 108 of the cannula 92. This force may expand thelongitudinal channel separating the first and second jaws 94, 96,thereby splaying the first and second jaws 94, 96 apart.

The first blade 4 may then be towed (e.g., pivoted) relative to thefirst arm 2 or a portion thereof (e.g., body 20), for example, byactuating the towing assembly 18 or a component thereof. The first blade4 may be towed about the rotatable shaft 28 (e.g., towed about a pivotpoint defined by a longitudinal axis thereof). As the first blade 4 istowed, the first arm 2 may advantageously not move with respect to theretraction site. The step of actuating the towing assembly 18 caninclude actuating the worm drive. The step of actuating the worm drivecan include applying torque to an actuator 42, such as a hex head,coupled to worm 38. As the actuator 42 is rotated, the rotational forcemay be transmitted to the worm 38. The rotating worm 38 may engage theworm gear 40 and cause the worm gear 40 to rotate about an axisperpendicular and/or orthogonal to that of the worm 38. Rotation of theworm gear 40 may cause the rotatable shaft 28 and interface member 26 torotate. As the interface member 26 may be intermeshed with the firstblade 4, rotation of the interface member 26 may cause the first blade 4to rotate.

Advantageously, this mechanism may enable the first blade 4 to be towedrelative to the first arm 2 at any angle (e.g., between 0 and 360degrees). In some embodiments, the first blade 4 may be towed relativeto the first arm 2 from a first position to a second position, whereinthe second position is in the range of from 1 degree to 360 degrees awayfrom the first position. In other embodiments, the first blade 4 may betowed relative to the first arm 2 from a first position to a secondposition, wherein the second position is in the range of from 1 degreeto 180 degrees away from the first position. In still other embodiments,the first blade 4 may be towed relative to the first arm 2 from a firstposition to a second position, wherein the second position is in therange of from 1 degree to 90 degrees away from the first position. Inyet other embodiments, the first blade 4 may be towed relative to thefirst arm 2 from a first position to a second position, wherein thesecond position is at least 90 degrees away from the first position.

Some embodiments may further include adjusting a vertical position ofthe first blade 4 (e.g., relative to a surgical site). As describedherein, the first arm 2 may include a plurality of pivot points. Thus,these embodiments may include bending and/or flexing the first arm 2,for example by pivoting the body 20 relative to the connector 24 and/orpivoting the connector 24 relative to the base 22.

Some embodiments may further include coupling the first arm 2 to therack 8. This step may include inserting the rack 8 into the base 22 ofthe first arm 2. The first arm 2 may then be translated, e.g., linearly,along the rack. In some embodiments, the first arm 2 may be translatedin one direction (e.g., lateral). In other embodiments, it may be alsotranslated in a second, opposite direction (e.g., medial). The first arm2 may be translated along the rack 8 by engaging (e.g., turning and/orrotating) actuator 62, as illustrated, for example, in FIG. 1B. Actuator63 may be used to translate second arm 12 along the rack 8. In someembodiments, as the actuator 62 is turned in a first direction, thetranslation member (e.g., pinion) may also rotate, engaging the teeth onthe rack 8, and the first arm 2 may then be translated in a firstdirection. In some embodiments, the first arm 2 may be translated in asecond, opposite direction by turning and/or rotating the actuator 62 inan opposite direction. Some embodiments can also include locking theposition of the first arm 2 along the rack 8. In some embodiments, thisstep may include engaging a locking member so as to clamp thetranslation member and/or rack 8.

In embodiments that include ratcheting assembly 160, the step oftranslating the first arm 2 along the rack 8 in a first and/or seconddirection can include activating or deactivating the ratcheting assembly160 as described herein. Some embodiments may include deactivating theratcheting assembly 160, for example, prior to coupling the first arm 2and first blade 4. The deactivating step may include depressing the pawl162 to a fully-released position as described herein. The first arm 2may then be subsequently translated. When the ratcheting assembly 160 isin the deactivated configuration, the first arm 2 may be configured totranslate freely (e.g., without interference from and/or simultaneouslydepressing pawl 162) in both directions.

Some embodiments may include activating the ratcheting assembly 160, forexample, after coupling the first arm 2 and first blade 4. Theactivating step may include depressing the actuator 166 as describedherein. When the ratcheting assembly 160 is in the activatedconfiguration, the first arm 2 may be configured to translate freely inone direction, and may be configured to translate in the other directiononly when simultaneously depressing the pawl 162 to a partially-releasedposition as described herein. In any of these embodiments, the first arm2 may be translated by engaging (e.g., rotating) pinion 164, forexample, with a hex driver, wingnut, or other type of driver.

Some embodiments may further include reversibly coupling the rack 8 to asupport structure, such as a table. This step may include coupling(e.g., clamping) the rack 8 to table mount 10, and coupling (e.g.,clamping) the table mount 10 to the support structure.

Those skilled in the art may appreciate that in some embodiments, one ormore of the steps described herein may take place in a differentsequence. For example, the first arm 2 may be coupled to the rack 8prior to coupling one or both blades to an arm and/or a handle (e.g.,prior to coupling the first blade 4 to the first arm 2 and/or firsthandle 6). Additionally, the rack 8 may be coupled to the supportstructure prior to coupling the rack 8 to one or both arms, and/or priorto coupling one or both blades to an arm and/or a handle.

An alternative embodiment of a blade attachment mechanism is provided inFIGS. 6A-8E. Instead of the set screw connection described above, theblade is reversibly attachable to the retractor arm using a quickconnection concept. The quick connect allows the surgeon to maintain theblade positioning while bringing in the retractor and locking thecomponents together. Blade placement prior to attaching to the retractorframe provides increased freedom and improved blade manipulationresulting in more ideal muscle and tissue retraction. In addition,locking is independent from the blade angle allowing for locking at anydesired angle.

As illustrated in FIGS. 6A-6F, the blade member 200 includes a connectorbody 202 and a blade 204 extending therefrom. The connector body 202extends from a first end 206 configured to engage with a portion of theretractor system 100 (e.g., towing assembly 218) to a second end 208along a longitudinal axis. The blade 204 may be offset from theconnector body 202 and projects from the connector body 202 proximate tothe second 208. The blade 204 may extend along a longitudinal axis thatis substantially perpendicular to the longitudinal axis of the connectorbody 202. The blade 204 may be of any type and shape suitable in the artfor retracting soft tissues and muscle. For example, the blades 204 maybe provided with a convexity at the proximal end to cup under tissue andmuscle to prevent the blades and retractor from moving out of position.

As best seen in FIGS. 6E and 6F, the connector body 202 includes anopening 210 in the first end 206 of the connector body 202. The opening210 extends into and is in fluid communication with an interior cavity212 of the connector body 202. The opening 210 and interior cavity 212are sized and configured to receive at least a portion of the rotatableshaft 228 (e.g., the portion of the rotatable shaft 228 projecting pastthe first end 222 of the towing assembly 218). The first end 206 of theconnector body 202 includes a plurality of protrusions (e.g., bumps,peaks, teeth, and/or ridges) and/or receptacles (e.g., valleys,channels, depressions, and/or grooves), or a star grind 214 as describedherein, extending radially around the opening 210 in the first end 206.The star grind 214 may advantageously be configured to intermesh and/orinterdigitate with the corresponding star grind surface 232 on thetowing assembly 218.

As opposed to the set screw locking mechanism, a spring-loaded buttonmechanism 250 is provided to lock the blades to the towing assembly 218at any desired position and release the blades. As best seen in FIGS. 6Band 6C, the spring-loaded button mechanism 250 includes a depressablebutton 252 and a spring 254 positioned within a cavity in the button252. As shown in FIG. 6D, the button 252 includes a first end 256configured to be depressed by a user and a second end 258, which isreceived in the connector body 202 in a locked position (FIG. 6E) andmay extend outside the connector body 202 when in an unlocked position(FIG. 6F). An opening 260 extends through the button 252, which is sizedand configured to receive at least a portion of the rotatable shaft 228of the towing assembly 218. The opening 260 may be non-symmetrical inshape. In particular, the opening 260 may have a key-hole type designwhere the opening 260 may include a channel or elongated area 262 with anarrower aperture. The elongated area 262 may have a smaller apertureproximate to the second end 258, and the opening 260 may have a largeraperture proximate to the first end 256 of the button 252. The largeraperture may be circular in form with a larger diameter than the widthof the elongated area 262. The larger portion of opening 260 may besized and dimensioned to receive the largest diameter section of therotatable shaft 228. The elongated area 262 may be defined by a curvedsurface 264 configured to contact and engage the groove 236 in therotatable shaft 228 of the towing assembly 218 when in the lockedposition. The curved surface 264 may be provided with a taper for theshaft 218 to push the button 252 into position during attachment ordisengagement. In addition to the automatic spring-loaded buttonmechanism 250, the blade member 200 is held in place by interferencebetween the star grind 214 on the blade member 200 with correspondingstar grind 232 on the towing assembly 218.

Similar to towing assembly 18, the towing assembly 218 shown in FIGS.7A-7D may include a body 220, an interface member 226, and a rotatableshaft 228. The body 220 extends from a first end 222 configured toengage the blade member 200 to a second end 224 terminating in aprojection 246 configured to pivotally couple to the connector 24 asdescribed elsewhere herein. The body 220 may include an axial hole 230and a cavity extending longitudinally therethrough along at least aportion of the length of the body 220. As illustrated in FIG. 7A, thebody 220 may receive the interface member 226 that includes the stargrind 232. The interface member 226 may be retained in position with oneor more pins 244 or other suitable coupling mechanism. The star grind232 may be formed by a plurality of protrusions (e.g., bumps, peaks,teeth, and/or ridges) and/or receptacles (e.g., valleys, channels,depressions, and/or grooves) which may be interspersed therebetween.Preferably, the star grind 232 on the interface member 226 should besized and dimensioned to correspond and interface with the star grind214 on the blade member 200. The interface member 226 may also includean aperture sized and dimensioned to receive a portion of the rotatableshaft 228 with the star grind 232 extending radially outward from theaperture. Thus, the rotatable shaft 228 may project outwardly from thefirst end 222 of the body 220 of the towing assembly 218.

The rotatable shaft 228, shown in FIG. 7C, may be positioned within thebody 220 and through the interface member 226 of the towing assembly218, for example, by passing through the axial hole 230 therein. Therotatable shaft 228 may extend from a first end 240 configured to bereceived within the blade member 200 to a second end 241 configured tobe received within the body 220 of the towing assembly 218. Therotatable shaft 228 can be generally elongate and/or at least partiallycylindrical. The second end 241 may be enlarged to have a greaterdiameter than the remainder of the shaft 228. A portion of the rotatableshaft 228, for example, proximate to the second end 241 and between thesecond end 241 and the groove 236 may be provided with an external hexconfigured to maintain alignment between all of the retractorcomponents.

As illustrated in FIG. 7C, the first end 240 of the rotatable shaft 228may include a tapered distal tip 234 with a circumferential channel orgroove 236 on an exterior surface thereof. The groove 236 may extendpartially or entirely around the circumference of the rotatable shaft228. In one embodiment, the rotatable shaft 228 is provided with a 360°notch or groove 236. When in the unlocked position, the groove 236 onthe shaft 228 is configured to be received within the enlarged opening260 in the button 252. In the locked position, the groove 236 isconfigured to be received within the elongated area 262 and contacted bythe curved surface 264 of the button 252. Thus, in the locked position,the curved surface 264 of the button 252 engages the groove 236 in therotatable shaft 228 and the star grind 232 of the interface member 226engages the star grind 214 of the connector body 202, thereby causingthe blade member 200 to be locked to the towing assembly 218. Even inthe locked position, however, the rotatable shaft 228 may be configuredto rotate about a longitudinal axis, for example, by driving or rotatingactuation member 242. Actuation member 242 is similar to actuator or hexhead 42 described herein.

The towing assembly 18 can include a gear assembly configured to applytorque or a rotational force to the rotatable shaft 28 and/or theinterface member 226. For example, the towing assembly 218 can include aworm drive or similar apparatus, for example, as discussed for towingassembly 18. The actuation member 242, configured to be engaged by adriver or wingnut, for example, can be used by a surgeon or otherpractitioner to apply a rotational force to transmit rotational movementto the rotatable shaft 228 and/or interface member 226, thereby causingthe blade 204 to tow or pivot, for example, by up to 360 degrees or morerelative to an arm of the system.

In addition to the features of the towing assembly 18 already describedherein, the towing assembly 218 may be modified to include aspring-loaded function. As best seen in FIG. 7D, a spring 238 isprovided within the cavity in the body 220 and behind the interfacemember 226. The spring 238 may include, for example, a coil spring, flatspring, v-spring, or any suitable type of spring mechanism known in theart. The spring 238, for example, in the case of a coil spring, may alsobe positioned around the rotatable shaft 228. Thus, the interface member226 having star grind 214 is spring-loaded. The spring-loaded interfacemember 226 may be configured to take up any inherent tolerances in theretractor and blade components to ensure a tight fit with thecorresponding star grind 214 on the blade member 200. When the buttonmechanism 250 in the blade member 200 is unlocked, the spring 238 causesthe blade member 200 to eject off the rotatable shaft 228 and separatefrom the towing assembly 218.

With further reference to FIGS. 8A-8E, the functionality of thespring-loaded button mechanism 250 and spring-loaded towing assembly 218will be described in more detail. FIG. 8A shows the blade member 200 andthe towing assembly 218 separated from one another with the buttonmechanism 250 in its relaxed state. The first end 256 of the button 252may be protruding or projecting outwardly from the connector body 202and the second end 258 of the button 252 may be recessed within theconnector body 202. As the rotatable shaft 228 is inserted into theblade member 200 or the blade member 200 is positioned onto the towingassembly 218, the star grinds 214, 232 will begin to mesh and the spring238 in the towing assembly 218 will begin to compress. FIG. 8B shows apartial position as the rotatable shaft 228 is inserted into the cavity212 in the blade member 200. The taper 234 on the first end 240 of theinternal rotatable shaft 228 will automatically slide the button 252downwards. The first end 256 of the button 252 may be moved downwardsuch that the second end 258 of the button 252 may be protruding orprojecting outwardly from the connector body 202. This allows for thewider section of opening 260 of button 252 to be exposed.

Once the shaft 228 of the towing assembly 218 is sufficiently insertedinto the blade member 200, the button 252 will spring up into the groove236 on the rotatable shaft 228 due to spring 254, thereby locking thetwo components together automatically. FIG. 8C shows the buttonmechanism 250 in the locked position and the spring 254 expanded. Thesecond end 258 of the button 252 is once again recessed within theconnector body 202 and the first end 256 of the button 252 is protrudingat a maximum height. In addition, the curved, tapered surface 264 on thebutton 252, also shown in the locked position in FIG. 6E, is receivedwithin the groove 236 of the rotatable shaft 228 to lock the blademember 200 to the towing assembly 218 and the retractor system 100. Theautomatic locking may provide both a visual and audible locking feature.In the locked configuration, as the actuation member 242 andcorresponding gear on the towing assembly 218 is rotated so is therotatable shaft 228 and all components connected to it through theexternal hex geometry on the rotatable shaft 228. Thus, rotation ofactuation member 242 and the gear causes rotation of the rotatable shaft228, rotation of the star grind 232, and correspondingly rotation of thestar grind 214 on the blade member 200, thereby causing towing orpivoting of the blade 204.

FIG. 8D depicts an un-locked position for the button mechanism 250. Torelease the blade member 200 from the retractor, the surgeon can depressthe button 252 in the direction of arrow 244 compressing spring 254,allowing the internal shaft 228 to be withdrawn, and the entire blademember 200 to be removed in the direction of arrow 248. The curved,tapered surface 264 is disengaged from the groove 236 on the shaft 228to unlock the blade member 200 from the towing assembly 218. Theun-locked position of the button 252 is also shown in FIG. 6F such thatthe larger portion of the opening 260 is revealed. The first end 256 ofthe button 252 is again moved downward such that the second end 258 ofthe button 252 is protruding or projecting outwardly from the connectorbody 202. The spring 238 behind the interface member 226 of the towingassembly 218 will act to eject the blade member 200.

FIG. 8E shows the blade member 200 ejected from the towing assembly 218,and thus separated from the retractor system 100. The button mechanism250 has also automatically returned to its original position due tospring 254, which is the same position as shown in FIG. 8A. Due to theconfiguration and quick connection concept described herein, attachmentof the blade member 200 does not require surgeon input or manipulationaside from lining up the rotatable shaft 228 to the opening 210 in theblade member 200. In addition, the locking mechanism is completelyautomatic.

According to other embodiments, a handheld retractor can utilize thesame blades as the midline retractor system described herein. In otherwords, a universal attachment may be selected which is suitable toconnect the same blades to both the midline retractor system and one ormore handheld devices. The universal attachment allows forinterchangeable use of a single blade type in multiple devices.

An embodiment of a radial handheld retractor 300 is provided in FIGS.9A-9H. Blade members 200 will be used for discussion purposes, but anysuitable blade type may be substituted if within the scope and spirit ofthe blades described herein. The blade members 200 will lock to thehandheld retractor 300 through the same mechanism as the midlineretractor 100. Similar to the functionality for the midline retractor100, the blade members 200 can also be locked at any desired angle.

As shown in FIGS. 9A-9H, the handheld retractor 300 may include firstand second handles 302, 304, each having a finger grip section, forexample, in the form of loops. First and second arms 306, 308 may berespectively associated with each of the first and second handles 302,304. A pivotal connection may be located between the first and secondhandles 302, 304 and the first and second arms 306, 308. Operation ofthe handheld retractor 300 may be such that movement of the handles 302,304 towards one another causes the arms 306, 308 to move away from oneanother as shown in FIG. 9G; and vice versa, movement of the handles302, 304 away from one another causes the arms 306, 308 to move towardone another, as shown in FIGS. 9A-9F.

A distal end of each of the first and second arms 306, 308 may include auniversal attachment mechanism or mount 310 configured to receive blademember 200. The universal attachment mount 310 may include the same orsimilar elements provided with the towing assembly 218 described herein,for example, including the rotatable shaft 228, star grind 232, andactuation member 242. Thus, the universal attachment mount 310 may beconfigured to mate with blade member 200 and provide the samequick-connect and towing functionality. If towing is not desired, theuniversal attachment mechanism 310 may include a non-rotatable shaft,for example, with the star grind mating feature to still provide forquick-connect and release of the blade member 200. Once the blademembers 200 are attached to the handheld retractor 300, a handheldcompression force may be applied to the handles to create a radialretraction at the incision site.

FIG. 9A shows the interchangeable blade members 200 before beingconnected with the universal attachment mechanism 310. FIGS. 9C and 9Edepict the retractor 300 with the blade members 200 connected such thatblades 204 are provided in a substantially vertical position. Etch marks318 may be provided on the blade member 200 and on the distal ends ofthe universal attachment mounts 310 to indicate when the blades 204 arein the vertical position as this position may be most desirable ifintroducing the blades 204 and retractor 300 to the incision sitealready preassembled. Similarly, FIG. 9B shows the interchangeable blademembers 200 before being connected with the universal attachment mounts310 in an offset position. FIGS. 9D and 9F depict the retractor 300 withthe blade members 200 connected in a towed or pivoted position. Thus,the blade members 200 can be locked to the retractor 300 at any desiredangle.

The handheld retractor 300 may further include a ratcheting thumb knob312 configured to lock the retraction at a desired position. A user maypush on the thumb knob 312 to release a locking pawl 314, therebyallowing the arms 306, 308 to freely travel in either direction. Inaddition, the universal attachment mechanism 310 may be pivotallyconnected to the arms 306, 308. As best shown in FIG. 9H, pivot point316 may be located on each retractor arm 306, 308 that will allow thehandles 302, 304 to be angled relative to the blades 204, thereby betterconforming to the patient's anatomy at skin level. The handles 302, 304and arms 306, 308 may extend along a first longitudinal axis, and thepivot point 316 may allow the universal attachment mechanism 310 toextend along a second longitudinal axis. Thus, the first and secondlongitudinal axes may be the same or the second longitudinal axis may beangled relative to the first longitudinal axis when the blade 204 ispivoted at pivot point 316.

An alternative embodiment of a handheld retractor 400 is provided inFIGS. 10A-10C. Similar to handheld retractor 300, handheld retractor 400can utilize the same blades as the midline retractor system describedherein. The blades can be attached at any angle and can be attachedprior to insertion into the incision, or after the blades are insertedin the incision, then the handheld retractor 400 can be attached. Again,blade members 200 will be used for discussion purposes, but any suitableblade type may be substituted if within the scope and spirit of theblades described herein. The blade members 200 can lock to the handheldretractor 400 through the same mechanism as the midline retractor 100.Similar to the functionality for the midline retractor 100, the blademembers 200 can also be locked at any desired angle.

As shown in FIGS. 10A-10C, the handheld retractor 400 may include firstand second handles 402, 404, each having a hand or finger grip section.First and second arms 406, 408 may be respectively associated with eachof the first and second handles 402, 404. A pivotal connection may belocated between the first and second handles 402, 404 and the first andsecond arms 406, 408. As opposed to radial retraction as provided byretractor 300, by compressing the handles, the blades will retract outparallel to one another. The first and second arms 406, 408 may eachinclude a pivot point distal to the pivotal connection. First and secondcross connectors 420, 422 may be provided between the first and secondarms 406, 408 to maintain the parallel retraction between blade members200. In particular, a first end of each of the cross connectors 420, 422is pivotally coupled to a first portion of the arms 406, 408 and asecond end of each of the cross connectors 420, 422 is slidably matedwith an elongate opening in a second portion of the arms 406, 408,thereby maintaining a substantially parallel relationship between thefirst and second arms 406, 408. Operation of the handheld retractor 400may be such that movement of the handles 402, 404 towards one anothercauses the arms 406, 408 to move away from one another in a parallelmanner; and vice versa, movement of the handles 402, 404 away from oneanother causes the arms 406, 408 to move toward one another in aparallel manner.

A distal end of each of the first and second arms 406, 408 may include auniversal attachment mechanism or mount 410 configured to receive blademember 200. The universal attachment mount 410 may include the same orsimilar elements provided with the towing assembly 218 described herein,for example, including the rotatable shaft 228, star grind 232, andactuation member 242. Thus, the universal attachment mount 410 may beconfigured to mate with blade member 200 and provide the samequick-connect and towing functionality. If towing is not desired, theuniversal attachment mechanism 410 may include a non-rotatable shaft,for example, with the star grind mating feature to still provide forquick-connect and release of the blade member 200. Once the blademembers 200 are attached to the handheld retractor 400, a handheldcompression force may be applied to the handles to create a parallelretraction at the incision site. With the blades 204 inserted into theincision and prepositioned in the desired location, the handheldretractor 400 can be introduced and locked on to the blades 204.Alternatively, if desired, the blades 204 and handheld retractor 400 canbe locked together prior to introduction at the incision site.

FIG. 10A shows the interchangeable blade members 200 before beingconnected with the universal attachment mechanism 410. FIG. 10B depictsthe retractor 400 with the blade members 200 connected such that blades204 are provided in a substantially vertical position. Etch marks 418may be provided on the blade member 200 and on the distal ends of theuniversal attachment mechanisms 410 to indicate when the blades 204 arein the vertical position. Similar to attachment mount 310, attachmentmount 410 is configured such that the blade members 200 can be locked tothe retractor 400 at any desired angle. As shown in FIG. 10C, andsimilar to retractor 300, a pivot point 416 may be present in both arms406, 408 to allow the parallel handheld retractor 400 to better conformto patient anatomy.

In addition, the retractor 400 may include additional features, such asa ratcheting pawl to lock the amount of retraction. For example, a lever412 on the back of the retractor 400 will ratchet as the handles 402,404 are compressed and can lock the retractor 400 at a desired position.The lever 412 may be pivotally coupled to the end of the second handle404 and ratchetably engageable with the first handle 402. To release theretraction and bring the blades 200 back together, the lever 412 can bemanually pulled away from the handle 402.

As shown in FIGS. 11A-11E, some embodiments may include using a wingnutattachment 500 to provide low-torque rotation, for example, of theactuators, actuation members, or hex heads described herein. Inparticular, the wingnut attachment 500 may be configured to engage, forexample, hex head 42 or actuation member 242 in order to tow or pivotthe blades. The wingnut 500 may be completely removable and detachablefrom the system entirely. When coupled to the hex head 42 or actuationmember 242, for example, the wingnut 500 may be positioned in a verticalposition or pivoted to the side. The wingnut 500 includes aspring-loaded mechanism including ball bearing 502 and spring 504 tohelp retain the wing 506 in the fully vertical position. In the verticalposition, the ball bearing 502 is nested within a cavity in the wing 506and engages with a detent 508 in the head 510. This vertical positionallows for low-torque rotating motion. Once movement is complete, thewing 506 may be pivoted to either side (e.g., to an orthogonal position)by manually moving the wing 506 as shown in FIG. 11D. To retain the hexhead 42 or actuation member 242 in the socket 512 in head 510, a nestedspiral retaining ring 514 may provide an interference fit with themating hex head 42 or actuation member 242. Once the wingnut 500 isinserted over the hex head 42 or actuation member 242, the interferenceof the retaining ring 514 will cause the ring to splay out, therebyincreasing the force to prevent them from separating. Notches may alsobe provided to increase the force required to remove the wingnut 500.

Advantageously, the retractor systems, handheld retractors, andassociated devices described above can be used with a number ofdifferent implants and devices. For example, the retractor systems anddevices can be used to provide access to a surgical site such that aprosthetic device that preserves motion can be provided. In addition,the retractor systems and devices can be used to provide access to asurgical site such that a fusion device, such as a cage or spacer, orstandalone device, can be provided. In addition, the retractor systemsand devices can be used to provide access to various other devices,including but not limited to rods, screws (e.g., pedicle screws,cortical screws, etc.), plates and various other implants that are usedin spine surgery.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims. Althoughindividual embodiments are discussed herein, the invention covers allcombinations of all those embodiments.

What is claimed is:
 1. A retractor system comprising: a first armcomprising a towing assembly, the towing assembly comprising aninterface member coupled to a rotatable shaft, wherein the interfacemember comprises a distal surface having a plurality of protrusions andreceptacles; a first blade member comprising a connector body and ablade extending therefrom, the connector body having an internal cavityconfigured to reversibly receive the rotatable shaft therein, whereinthe first blade member comprises a plurality of protrusions andreceptacles configured to intermesh with the plurality of protrusionsand receptacles of the distal surface of the interface member; and aspring-loaded button mechanism configured to lock the first blade memberto the first arm at any desired position, wherein the spring-loadedbutton mechanism includes a depressable button and a spring positionedwithin a cavity in the button, the button includes a first endconfigured to be depressed by a user and a second end which is receivedin the first blade member in a locked position; wherein the rotatableshaft is configured to rotate about a longitudinal axis; wherein theinterface member of the towing assembly is spring-loaded.
 2. Theretractor system of claim 1, wherein the button defines an openingextending therethrough which is sized and configured to receive at leasta portion of the rotatable shaft.
 3. The retractor system of claim 2,wherein the opening in the button is non-symmetrical in shape.
 4. Theretractor system of claim 2, wherein a portion of the opening is definedby a curved surface configured to engage a groove in the rotatable shaftwhen in the locked position.
 5. The retractor system of claim 1, whereina spring is provided within a cavity in the towing assembly behind theinterface member.
 6. The retractor system of claim 5, wherein when theblade member is unlocked, the spring is configured to cause the blademember to eject off the rotatable shaft and separate from the towingassembly.
 7. The retractor system of claim 1, wherein the towingassembly further comprises an actuation member configured to tow theblade.
 8. The retractor system of claim 7, wherein the actuation memberis configured to be engaged by a removable wingnut to provide alow-torque rotation.
 9. The retractor system of claim 8, wherein thewingnut includes a spring-loaded mechanism including a ball bearing anda spring to help retain a wing in a vertical position.
 10. A retractorsystem comprising: a first arm comprising a first towing assembly, thefirst towing assembly comprising a first interface member coupled to afirst rotatable shaft, wherein the first interface member comprises adistal surface having a plurality of protrusions and receptacles; afirst blade member comprising a connector body and a first bladeextending therefrom, the connector body having an internal cavityconfigured to reversibly receive the first rotatable shaft therein,wherein the first blade member comprises a plurality of protrusions andreceptacles configured to intermesh with the plurality of protrusionsand receptacles of the distal surface of the first interface member; anda spring-loaded button mechanism configured to lock the first blademember to the first arm at any desired position, wherein thespring-loaded button mechanism includes a depressable button and aspring positioned within a cavity in the button, the button includes afirst end configured to be depressed by a user and a second end which isreceived in the first blade member in a locked position; wherein thefirst rotatable shaft is configured to rotate about a longitudinal axis;wherein the first interface member of the towing assembly isspring-loaded; a second arm comprising a second towing assembly, thesecond towing assembly comprising a second interface member coupled to asecond rotatable shaft, wherein the second interface member comprises adistal surface having a plurality of protrusions and receptacles; asecond blade member comprising a connector body and a second bladeextending therefrom, the connector body having an internal cavityconfigured to reversibly receive the second rotatable shaft therein,wherein the second blade member comprises a plurality of protrusions andreceptacles configured to intermesh with the plurality of protrusionsand receptacles of the distal surface of the second interface member;and a rack, wherein the first and second arms are configured totranslate along the rack, thereby allowing the first and second blademembers to retract tissue.
 11. The retractor system of claim 10, whereinthe button defines an opening extending therethrough which is sized andconfigured to receive at least a portion of the first rotatable shaft.12. The retractor system of claim 11, wherein the opening in the buttonis non-symmetrical in shape.
 13. The retractor system of claim 11,wherein a portion of the opening is defined by a curved surfaceconfigured to engage a groove in the first rotatable shaft when in thelocked position.
 14. The retractor system of claim 10, wherein a springis provided within a cavity in the first towing assembly behind thefirst interface member.
 15. The retractor system of claim 14, whereinwhen the first blade member is unlocked, the spring is configured tocause the first blade member to eject off the first rotatable shaft andseparate from the first towing assembly.
 16. The retractor system ofclaim 10, wherein the first towing assembly further comprises anactuation member configured to tow the first blade.
 17. The retractorsystem of claim 16, wherein the actuation member is configured to beengaged by a removable wingnut to provide a low-torque rotation.
 18. Theretractor system of claim 17, wherein the wingnut includes aspring-loaded mechanism including a ball bearing and a spring to helpretain a wing in a vertical position.